manuel75o / flutter_bluetooth_manager

The aim of FlutterBluetoothManager is to handle multiple devices and their streams with ease. It is built on top of the Flutter Bluetooth Package FlutterBluePlus.

The aim of FlutterBluetoothManager is to handle multiple devices and their streams with ease. It is built on top of the Flutter Bluetooth Package FlutterBluePlus.

BluetoothManager

The BluetoothManager creates a DeviceModel. This represents the device and it's corresponding Services and Characteristics. A device is unique to a DeviceModel. There can be multiple Services and Characteristics per DeviceModel.

The general Structure looks like this:

class DeviceModel {
  final BluetoothDevice device;
  final List<BluetoothService> services;
  final List<CharacteristicStream> characteristicsStream;
  DeviceModel(this.device, this.services, this.characteristicsStream);
}

CharacteristicStream contains the BluetoothCharacteristic and Info wether it's Stream is initialized.

class CharacteristicStream {
  final BluetoothCharacteristic characteristic;
  bool isInitialized;
  CharacteristicStream({
    required this.characteristic,
    this.isInitialized = false,
  });
}

Features

Following pictures shows the example of the BluetoothManager.

Getting Started

To get started you simply create an instance of the

BluetoothManager:

BluetoothManager bluetoothManager = BluetoothManager();

Connect a device:

bluetoothManager.connectDevice(BluetoothDevice device);

Disconnect a device:

bluetoothManager.disconnectDevice(BluetoothDevice device);

Check device ConnectionState:

A common problem is, if you accidently lose connection to a device it can lead to an exeption. With this function you constantly check the device connectionState for all connected devices and if it loses a connection the device will be disconnected and removed from the DeviceModel preventing exeptions or potential errors.

bluetoothManager.checkDeviceConnection();

Get Characteristic:

To retrieve a Characteristic for subscribing to a stream or writing message you can perform this by calling getCharacteristic. Since there can be multiple Characteristics per Service you can choose it by Number.

bluetoothManager.getCharacteristic(BluetoothDevice device, int characteristicNumber);

Open Stream

To receive a stream you need to call the openStream function. It takes a characteristic and returns/yields a Stream<List<int>>.

bluetoothManager.openStream(BluetoothCharacteristic? characteristic);

StreamHandler

You can handle multiple streams by simply calling the streamHandler. It takes the device index value and a stream as input. You need to use the stream of openStream.

bluetoothManager.streamHandler(index, stream);

Get Stream

Retrieve a stream for Streambuilder by its device index

bluetoothManager.getStream(index)

Close a stream

bluetoothManager.closeStream(index)

Additional information

Tested with IOS17.

flutter_bluetooth_manager's Issues

Got problems when running it, most likely some dependencies and environment setup issues, pleaes help

Hi Manuel,

I got it cloned to my local directory, and I have tried the followings:

1. running it on edge and chrome, and it seems not to find any bluetooth devices while I have two cell phones are in discovery mode
2. tried to run it with android "Pixel_3a_API_34_extension_level_7_x86_64 mobile emulator", I have got the following in DEBUG CONSOLE:
   Launching lib\main.dart on sdk gphone64 x86 64 in debug mode...
   C:\Users\rober\MyDevSandBox\flutter_bluetooth_manager\example\android\app\src\debug\AndroidManifest.xml Error:
   uses-sdk:minSdkVersion 19 cannot be smaller than version 21 declared in library [:flutter_blue_plus] C:\Users\rober\MyDevSandBox\flutter_bluetooth_manager\example\build\flutter_blue_plus\intermediates\merged_manifest\debug\AndroidManifest.xml as the library might be using APIs not available in 19
   Suggestion: use a compatible library with a minSdk of at most 19,
   or increase this project's minSdk version to at least 21,
   or use tools:overrideLibrary="com.lib.flutter_blue_plus" to force usage (may lead to runtime failures)

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':app:processDebugMainManifest'.

Manifest merger failed : uses-sdk:minSdkVersion 19 cannot be smaller than version 21 declared in library [:flutter_blue_plus] C:\Users\rober\MyDevSandBox\flutter_bluetooth_manager\example\build\flutter_blue_plus\intermediates\merged_manifest\debug\AndroidManifest.xml as the library might be using APIs not available in 19
Suggestion: use a compatible library with a minSdk of at most 19,
or increase this project's minSdk version to at least 21,
or use tools:overrideLibrary="com.lib.flutter_blue_plus" to force usage (may lead to runtime failures)

• Try:

Run with --stacktrace option to get the stack trace.
Run with --info or --debug option to get more log output.
Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 6s
─ Flutter Fix ─────────────────────────────────────────────────────────────────────────────────┐
│ The plugin flutter_blue_plus requires a higher Android SDK version. │
│ Fix this issue by adding the following to the file │
│ C:\Users\rober\MyDevSandBox\flutter_bluetooth_manager\example\android\app\build.gradle: │
│ android { │
│ defaultConfig { │
│ minSdkVersion 21 │
│ } │
│ } │
│ │
│ Following this change, your app will not be available to users running Android SDKs below 21. │
│ Consider searching for a version of this plugin that supports these lower versions of the │
│ Android SDK instead. │
│ For more information, see: │
│ https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration │
└───────────────────────────────────────────────────────────────────────────────────────────────┘
Exception: Gradle task assembleDebug failed with exit code 1

Please help... Appreciated...